Internal-combustion engine.



` G, K. umm. INIEHNAUCOMBUSTION ENGINE.

` Awulcmm man mv. z2. 1912.

1,2 2,051. meme@ 05u24, ma.

2 SHEETS-SHEET 1.

` ATTORNEY? GEORGE K. DAVOL, OF SAN FRANCISCO, CALIFORNIA.

INTERNAL-COMBUSTION ENGINE. ,f' 4

i Specification of Letters Patent.

l Patented oct. 24, 1916.

Application filed November 12, 1912. Serial N o. 730,883.

To all whom t 'may concern.'

Be it known that I, Gnonen K. DAvoL, a citizen of the United States, residing in the city and county of San Francisco, in the State of California, have invented a new and ,useful form of Internal-Combustion Engine,A

of which the'ifollowing forms a specification.

My invention particularly relates to a form of construction whereby the piston of an internal combustion engine may be sealed with water, or the sliding relation between the working cylinder and piston may be made gas tight by the introduction of water between their surfaces, the water at the same time cooling the surfaces, eliminating oil lubrication of the surfaces, and introducing some water vapor into the cylinder. My invention affords a means of accomplishing these and other ends in a practical and advantageous manner.

In the accompanying drawings: Figure 1 is a sectional view taken on the axis of the cylinder and piston of a vertical engine embodying my invention, and showing only the upper part of the engine, the lower part embodying the crank shaft and other parts having no direct bearing on my invention, I have shown broken away. F 2 is a cross-section taken at right angles to the section shown in Fig. 1 and on the line X-X in Fig. 1.

Similar parts are designated by the same reference numbers in all the drawings.

I herein show and describe my invention as applied to a two-stroke cycle internal combustion engine in which fuel is injected into the c \,'linder at or near the point of highest compression ot' the air. I consider my invention particularly applicable to this -form of engine but it may also he applied toa four-stroke cycle engine and to internal combustion engines in which many different cycles are. carried out. Such applications will be evident. l.

Referring to the drawings. the frame of the engine comprises two side columns 1 and 2, which are joined at their upper ends. This upper end of the. frame is bored to receive the working cylinder 3. which .is properly fitted and secured in place. Tir cylinder is supplied with charging and scavenging air from any suitable source through the passage 4, which communicates with the cylinderhead space from which it is admitted into the cylinder or working chamber through suitably actuated Valves, which having no direct bearing on my invention I have not shown. In the center of the cylinder head I have shown the lower portion yofr the fuel valve 6. The space 7 within the 6p cylinder head represents a 'water jacket. The working cylinder or chamber 3 is thus held rigidly at its upper end by the frame while its lower end extends down between the side columns of the frame. columns 1 and 2 are faced off on their inner sides to yprovide fiat sliding surfaces or guides for a cross head 8, which reciprocates between them. Side guiding strips 9,. Fig.

2, are attached tothe columns and assist in guiding and retaining the cross head.

A wrist pin 10 is properly held in place in the cross head in any of the usual manners and to this wrist pin the upper end of the connecting rod 11` is connected. The lower 75 end `of the connecting rod is connected to the main crank of the engine' in the usual manner and together with all lower parts of the engine isl not shown. It is sufficient .to

assume the cross head 8 reciprocated by the 80 guides usual connections, between the formed by the columns 1 and 2.

To the cross head S is rigidly attached in a suitable manner the working piston or plunger 12. This piston or plunger is of 8'5 somewhat smaller diameter than that of the main bore of the cylinder or working chamber, so then when reciprocated within the cylinder it does not come in contactwith" the stationary or rigid walls of the cylinder .no or working chamber at all, but allows of a @if clearance space between itself and the said walls.

A ring 13 is loosely carried bythe cylinder and within this ring the plunger 12 reg5 ciprocates. The inside diameter of the ring is very slightly in excess of the diameter of the plunger 12, so that there may be or there may not be actual contact between the ring and the piston or plunger, as running condi- 10e.

tions may determine. The 'ring 13 is solid and continuous and Iis not intended to clamp or grasp the plunger.

The working chamber by which I mean that portion of thepart 3, which sustains the pressure of the ,Working gases, opens at its lower end into the exhaust passage .or exs haust chamber l i, from which exhanst open- These side 65 ings 15, Fig. 2, on either side, lead the exhaust gases away. The ring 13 is held partly within the said working chamber and partly extending into the exhaust space'and is sustained in place by the screw threaded holding ring`16, against which a shoulder on the ring 13 rests and through. whlch the thinner lower end of the ring 13 extends. It

- will be understood that the ring 13 is loosely y held and has clearance between itself1 and the parts which hold it to. move sidewlse, or to adapt itself to the position of the working piston or plunger. n

The piston or plunger 12 1s shown 1n Fig. 1, at the upper end of its stroke. At the lower end of the stroke the upper end of the Vplunger 12 does not pass entirely out of the ring 13, but it descends low. enough to pass or uncover the exhaust ports or openings 17, formed in the ring 13, w h1ch open1ngs are shown partly by dotted line, 1n F1g. 1, or in section, in Fig. 2. At the lowest point of its stroke the upper end of the piston or plunger is still.within`.t hat portion of `the ring 13, which is below)v its said exhaust ports. f

\ The walls of the lower end of the exhaust chamber 14, approach but do not come in contact with the piston or plunger,12. Ay

lower ring 18, is held'loosely in the same manner in which the ring 18 is held and may or may not be in actual contact with the piston or plunger 12. This ring acts to prevent escape of exhaust gases around the iston or plunger from the exhaust chamer. The lower ring 18 is sustained in the recess provided by the holding ring 19, Which is secured to the walls of the exhaust ychamber by any suitable means.

`It is now seen comprehensively that the working piston or plunger 12, rigidly at- 12, with or without tached to the guided cross head 8, reciprocates within the working cylinder or cham* ber and the exhaustv chamberwithout contact with their walls, and that two loosely iloating rings 13 and 18 encircle the plunger actual contact withit but with very small clearance, and act to ciose the lower end of-the working chamber and the lower end of the exhaust chamber respectively. Both these rings 13 and 18 4,are solid and continuous and are made with an inside diameter 'very little in excess of the outside diameter of the plunger 12, and

VA,great accuracy could aet'wi'thout actual contactA with the all parts were properly adjusted with plunger, but they arermade Heating, or loosely heldto permit of their adapting themselves to any side movement that the piston or plunger may make.

To seal the clearance which theremay be between the-ring'13 and the plunger, and between the ring and the walls of thecyl'inder or working chamber, against egress ofthe working gases, water 1s used, whlch sealing v.water is introduced into the working chamber between the walls of the chamber and the piston or plunger 12, in the manner I will now describe. The working piston or plunger 12 has formed in its upper end an annular passage `20, from' which a number of small holes 21 open into a circular groove 22 turned on the outside of the piston. A pipe23 connects the said annular passage with `a passage 24 in the cross head 8. A

opens into a valve chamber 29, in which a check or suction valve 30 prevents water flowing from the chamber outwardly, but permits water to be drawn from a source of supply into the chamber 29 and pump barrel through the supply passage 31.

It can now be seen comprehensively that on the downward stroke of the cross head, which corresponds to the working stroke of the piston or plunger 12, the pump plunger 25 moves down within the pump barrel 28, and causes the Water to be drawn into the pump barrel through the suction valve 30, the valve 27 remaining on its seat. On, the return or upward stroke of the cross head which corresponds tothe compression stroke of the piston or plunger 12, the pump plunger 25 rises, the valve 3() closes on its seat, and water is forced through the Valve 27, passage 24, pipe 23, annular passage 20, and out through the small holes 21. The water so forced out through the small holes during theoretically the entire upward stroke of the reciprocating parts of the engine, is expelled first into the exhaust chamber through the ports 17, as the plunger is first in its lower position. As the plunger 12 rises and the groove 22 is covered by the ring 13, the expelled water fills the groove 22, and the grooves shown formed on the inside of the ring 13, which are formed to receive this water. As the plunger l2 rises further and the groove 22 comes above the ring `13, the water is for the remainder of the stroke forced into the clearance space between the plunger 12 'and the walls of the working'ehamber above the' ring 13. On

the succeeding or downward stroke, the prespiston or plunger i greater clearance.

the rush of the escaping gases carries the remaining water with it into the exhaust`- passages.

I am now able to explain thatl Whilethe ring 13 as before stated is loosely held-and as far as any positive andunyielding means 1s concerned, may or may not be in actual contact with the reciprocating piston, it is.

1n normal operationnot intended to come in -actual contact with the piston or plunger,

pressure results when pressure is utilized to impart velocity to the Huid. 'To render this clear it may in the first place be assumed 'that the ring 13 be separated from the pisexaetly the'same clearance on all' ton by sides. The escaping water will then flow through this clearance on all sides of the piston with a uniform velocity, and the total pressure of' the water between the ring 13 and the piston 12 will be uniform on all sides. If now we assume the ring 13 -to be slightly displaced relative to the piston l2,

. A so that thetwo are no longer exactlyI concen, 35

trically disposed, but that there exists a greater clearance between them `on one side than on the opposite side, then the velocity of the issuing water will be greater on the side havin the larger `clearance than on the opposite side having smaller clearance. This is a demonstrated fact and is due' to surface friction. It also follows that the pressures of the issuing water. between ring and piston will be less on the sidewhere it has the greater Velocity of flow, oronthe side of This latter effect follows from the well-known physical action above referred to, that when static pressure is'utilized to produce velocity in a fluid the static pressure of that portion of the fiuid to which such velocity or lsuch increased'velocty is imparted is reduced. This is very clearly demonstrated by the action of the well-known Venturi tube. This inequality of prpssure of the water escapin between the ring 13 and the piston or p unger 12 will tend to move the ring sidewise and to equalize the clearance between' the piston and ring on all sides, and so will tend to keep them from actual contact. y strength of this centering action, due to water escaping under high pressure, is very great. It.A must be realized, in order to clearly understand this action, that the same pressure of gases is applied to the water on clearance is the same This escaping water owing bev pansion of the gases takes place.

The

all side'sof 'the piston, so that the initial pressure which forces the water through the on all sidesf rThe velocity of the water, therefore, isv alone ypro- 'portional tothe frict'ional resistance'y which 1t encounters in flowingthrough the clearance space. This frictional resistance is clearance' space the closer the confining surfaces are brought together. The staticpres-l sure of the water at any portion of the clearvgreater, per unitof cross-sectional area of I ance space therefore varies inversely with its velocity and is therefore greater on the side of small clearance, if any inequality of clearance exists. This space between the ring 13, which forms part of the working cylinder, and the piston or plunger 12, is

designed to be very small, but at the same time it will be realized that it should be a sensible and definite space through which there will be a rapid flow of' the sealing water. I have extensively experimented with the velocity of flow of water through such small annular spaces, using clearances which Varied from 1gthousandths of `an inch to over12 thousandths of an inch, and at present I prefer to use for a piston of, for example, 16 inches in diameter, a clear` ance between it andthe encircling ring of' less than ten thousandths of an inch. With larger diameters of piston and with long strokes where the length of the ring"'13 can be relatively increased, the allowable amount of clearance could be increased, while for a smaller piston or a relatively short ring 13 the clearance would be made less. f

I wish to .make clear the point that, valthough the clearance between piston 12and encircling ring 13 isintended to be small,` still it is always a sensible and denite clearance, properly by the terni free, and definitely provided to permit the action of the escaping water to tend to prevent actual contact between the piston and ring. I also wish to make clear that, in accordance with the statement I have hereinbefore made, that the working defined, in my opinion,

ginev consists of that part or parts which, together with the. piston, sustain the pressure of the working gases; it necessarily follows that the floating ring 12 11i-ust be regarded as forming part of the working l chamber, inasmuch as this ring sustains the pressure of the working gases and formsgl with the piston or plunger, a chamber of variable volume, within which the useful ex- The inside surface of the ring should, therefore, properly be regarded as forming Vpart of the walls ,of the working chambers. If the ri ng 13 be made of relatively greater length than shown in Fig. 1,` this fact becomes particularly apparent.

. Therewill be of course some leakage between the pump plunger and the pump barrel. This leakage can by good workmanship be reduced to a very small amount which amount can be determined Vand allowed for. I have, however, provided to care/for this leakage in the following manner: It will be seen in Fig. 1 that the pump plunger, 25, extending upwardl from the cross head 8, extends through anr opening provided with a stuffing box 32,- in the lower side of the exhaust chamber, also that the ump barrel 28, extending down from above, where it is secured to the frame of the engine, passes through a hole in the upper side of the exhaust chamber, so that the pump plunger and pump barrel come together or telescope with each other within the exhaust chamber 14. Any leakage between the pump plunger and barrel will therefore occur within the exhaust chamber 14, and will be led or drained or carried away with the main body of the sealing water Iby the `exhaust gases.`

As shown in Fig. 2, a special extension 33, of the exhausty chamber 14, is madeto receive the pump plunger jand barrel, and this extension 33, may be regarded either as `a separate chamber in open connection with vthe exhaust chamber or passages, or as a portion of the exhaust chamber. The stuff,- ing box 32 can be replaced by any other suitable form of packing. It will also be recognized that it is immaterial whether the pump plunger be attached to the cross head S and the pump barrel be held stationary as shown in Fig. l, or the pump barrel be attachcd to the cross head and the pump plun ger be held stationary as their action will be the same in either case.

The long cylindrical pump barrel can of course be replaced by a chamber of any form desired and a stuffing box can be used, b'ut the form I show in Fig. 1 is the arrangement I prefer and it will of course be recog` nized that many equivalent arrangements for carrying out the essential ideas may be used.

In these snecications and in the claims which follow I use the term working chamber to express what is commonly known as the working cvlinder 'of an engine, as I regard the term working chamber as more descriptive of a part which may or maynot be of cylindrical form, although I regard and inten'd the two terms in this application lto an engine as synonymous, and to desi nate that part which forms with the woring piston a chamber of variable volume .within which the useful expansion of the `working gases takes place. I regard and intend the application of either of these terms to be properly limited to thatpart vwhich Atogether with the piston sustains the pressure of the working gases. In the construc- `tion shown in Fig. 1, therefore, the working cylinder or working chamber terminates where it enters the exhaust chamber and the walls of the exhaustrchamberl do not form 4in a proper sense a part of the work-l ing cylinder or Working chamber. I make this explanation here to avoid misunderstanding of my claims.

I have shown and describedmy invention embodied in a vertical engine which is the preferred form but its application is not limited to ai vertical engine. and the term substantially vertical which occurs in the claims which follow, I intend to cover a considerable deviation from a perfectly vertical position; the limiting angle to such deviation can only be determined by experience. It should also be recognized that although into the exhaust chamber and having exhaust ports and a portion below or beyond the exhaust ports, is n iy preferred form, still it could if desired be cut off at the exhaust ports sothat'at thebottom of the stroke the piston or plunger 12 would be entirely withdrawn from the ring. If so cut off it of course-will be raised so that it would be wholly within the working. cylinder or chamber without extension into the exhaust chamber. While such construction would sacrice certain advantages possessed by the form' I show and prefer, such a modifica-' tion could be adopted -without departing from the essential ideas of my invention. I do not limit myself to the exact constructions shown but may employ any equivalents without departing from the spirit of my invention.

What I claim is:

1 Iyn a substantially vertical internal combustion engine, the combination of a structure comprising a working :chamber and an exhaust passage, a plunger reciprocating within said structure, a ring loosely encircling said plunger and loosely held wholly or partly above said exhaust pasthe ring 13, in the form I show it, extending f* 11( sage, said plunger being guided to move wlthout contact with said structure above said exhaust passage,pand means for intron ducmg water into said chamber above said said ring. s

3. In an internal combustion engine, thev combination of a working chamber opening at one end into an exhaust passage, ajrecip-jgao introducing water into said -chamberabove rocating plungerexternally guided to move within said chamber, a loosely held ring embracing sald plunger and forming a part of the walls of said chamber, and means for introducing water into said chamber between said plunger and the walls of said chamber.

4. In an internal combustion engine, the combination of a working chamber opening a one end into an exhaust passage, a reciprocating plunger guided t'o move within but outf'of pontact with the upper side walls of said chamber, a solid continuous ring loosely held wholly or partly within said chamber and loosely fitting said, plunger, said ring forming the lower side walls of said chamber and means for introducing water into said chamber between said piston and the walls of said chamber. Y 5. In an internal combustion engine, the combination of a reciprocating plunger, an

exhaust passage surrounding said plunger,l

6. In an internal combustion engine, a working chamber or cylinder, a plunger reciprocating within said chamber or c linder, therebeing a free clearance space between said plunger and the walls-of said chamber, said plunger and a portion of said walls having limited freedom of relative lateral movement and means for introducing a rapidly moving or issuing annular ow of water through said free clearance space, forv maintaining freedom from contact .between said plunger and the Walls of said chamber.`

7. In an internal-combustion engine, a working chamber, the said workin chamber comprising walls which are aterally yieldable, a plunger, reciprocating within said chamber, the said plunger being guided by means external to said chamber, means for maintaining a clearance between said walls of said chamber and the plunger, andV means for introducing water into said Vclear-k ance.

8. In'- an internal-combustion engine, a working chamber, thewalls of which are partly formed by a laterally-yieldable ring,

a plunger reciprocating within said chamber. n vand guided by means external toy said chamber, and means for introducing water between said plunger andthe walls of said chamber.

9. In an internal ccmbustionengine,f,the`l` combination of a working chamber openmg .at one end into an exhaust passage, a recipl rocating working piston or plunger guided to move within but out of Contact with the walls of said chamber, the walls of said chamber comprising a ringloosely fitting said working piston or plunger, rsaid ring having a continuous external shoulder separating a thicker end from a thinner portion, said shoulder resting upon a retaining part secured to said working chamber, @il the thinner portion of said ring extending through said retaining 'part into said exhaust passage, together with means for introducing vwater into Athe working cylinder or chamber between its walls and said piston or plunger.

1 10. In an internal combustion engine, the combination of an exhaust chamber, a working chamber` opening into 'said exhaust chamber, a plunger passage opening into said exhaust chamber in line with said work- 3g, ing chamber, a reciprocating plunger moving within said plunger passage and within said working chamber but guided to have no contact with the walls of said plunger passage or with the walls of said working 9o A chamber, two rings loosely fitting said plunger, one of said rings being loosely held wholly or partly within said working chamber, and one of said rings being loosely held wholly or partly within said plunger passage, and means for introducing water between said plunger and the walls of said working chamber.

11. In a substantially vertical internal combustion engine, the combination of a 10o Working chamber opening at its lower end into an exhaust passage, avreciprocating plunger guided to move within said working chamber without contact with its walls,

said walls comprising a ring loosely held to o5 form a continuation ofv the walls of said chamber and loosely fitting said plunger, said plunger being entirely withdrawn from f the part of the chamber above the ring at the end of its working stroke, and means for in'- 11o troducing ,water between said plunger and the walls of said chamber.

12. In an internal combustion engine, the l combination of a working chamber opening at one end into an exhaust passage, a recip- 11,5 rocatingplunger guided to move within said working' chamber Without contact with,` its walls, said walls comprising a ring lloosely 'held to forma part of the walls of'said chamber-and loosely fitting said plungelglm)vl said ring extending into said exhaust pas- I sage, and means' for lntroduclng water bechamber.

.tween vsaid plunger `anclthe walls `of said' n 13. In an internal combustion engine, the 1215vv I combination of a working chamber opening at one fend into an exhaust passage, a reciprocating l-plunger vguided to move within said chamber without contact with its walls, said walls comprising `a ring loosely held and extending into said exhaust passage, said ringloosely fitting said plunger and having exhaust lports or openings in it, and means for introducing water into said Work- ,ing Icha-mber between said plunger and the walls of said chamber.

' 14. In 1an internal' combustion engine, the combination of a vworking cylinder or cham ber, a working pistonY Or-] lunger reciprocating Within said cylinder or chamber and being separated therefrom by a free annular clearance space, -means for maintaining said 'terthrough said orifice or. orifices into said clearance space to seal'the same.

, 15'. In a substantially vertical internal combustion engineinwhich Water is introduced into la lclearance space between the working p istonor plunger and the Walls of Athe Working cylinder, the combination of a pump plungeintele'scoping with a pump barpassage. v35

.said exhaust chamber or rel, one of the tivo said pump parts being rigidly connected at its lower end to the reciprocating lparts of the engine and the other of the two said pump `'parts being held stationa1y;`and an exhaust passage' intoV which the Working cylinder exhausts, the two said pump parts telescoping within said exhaust I16. In lan internal combustion engine in which Water is pumped into the Working cylinder, the combination 'of a pump plunger telescoping withiri'a pump barrel, and an exhaust chamber or passage into which the working cylinder exhausts, one of the two said pump parts being connected at one end to the reciprocating parts of the engine and passing` through a hole in the Walls ofthe passage, the other being held stationary, and means to dis-` charge the water from said pump barrel into said working cylinder.

17. In an internal combustion engine in which water is pumped into the Working cylinder, the combination of a Working cylinder having a chamber forming a part of, or in open connection with the exhaust passage of thev engine, a pump plunger,`a pump barrel, the two said pump parts telescoping with each other within said chamber and means to discharge Water from said pump barrelinto said Working cylinder.

18. In an internal combustion engine in which water is pumped into the working cylinder, the combination of a Working cylinder, a pump plunger, a pump barrel, a chamber forming part of or in open connection with the exhaust passages of the engine and having an opening in its Walls provided with a stuiiing box or other packing device,

and stuiiing box or other packing device,

and telescoping with the other of the two said pump parts Within the said chamber and means to discharge Water from said pump barrel into said working cylinder.

19. In an internal combustion engine, the

combination of a Working cylinder having an exhaust passage, a Working chamber open# ing at one end into said exhaust passage, a, reciprocating plunger guided to move Within said chamber .Without contact With its walls, and a loosely held ring forming a part of said Walls and extending into said exhaust passage, said ring loosely fitting said plunger and having exhaust ports or openings in it.

Q0. In an internal combustion engine, the combination of a Working chamber or cylinder opening at one end into an exhaust passage, a reciprocating plunger guided to move within said chamber Without contact with its walls, a ring loosely held by the walls of said chamber and loosely fitting said plunger, the said plunger having a water passage within it and orifices opening from said water passage through the Walls of the said plunger into the said Working chamber or cylinder.

21. In an internal combustion engine the combination of a Working chamber or cylinder opening at one end into an exhaust passage, the Walls of the said chamber or cylinder having an inwardly projecting continuous iange or lip, a reciprocating plunger guided to move Within said Working chamber Without contact with its walls and a solid continuous ring loosely resting on the said iange or lip and loosely tting the said plunger.

22. In combination, a rigid frame, a working cylinder comprising a Wall movable laterally with respect to the piston, a Working piston of a' diameter uniformly smaller than the diameter of said cylinder., and means to guide said piston to maintain the piston and the Walls of the cylinder out of contact.

23. In combination, a rigid frame, a working cylinder on Isaid frame, said cylinder having part. of its Walls rigid and another part of its Walls laterally adjustable, afworking piston of a diameter less than that of the Walls, guiding means on said frame for guiding said piston within said ycylinder and out of Contact therewith, and means for maintaining the laterally adjustable walls out of contact With said piston and for preventing the passage of working gases therebetween.

24. In an internalcombustion engine, a a working cylinder havmg al- .'rigd portion'and a laterally yielding porri gid frame,

tion, a Working piston of a diameter lese i than the diameter of the cylinder, and means 330 erally,

prising an annular flow of Water for maintaining the piston ont of Contact With said laterally movable Wall.

In Witness' whereof, I my name, this 2nd day of November A. D., 1912. f

GEORGE K. DAVOL.

Wibnesses W. W. HEALEY, y G. M. PAGE.'

hereunto subscribe i 

